Thermal Conductivity of Manganin Between 10 mK and 54 mK

Abstract

The thermal conductivity of Manganin (Cu 86 %, Ni 2 %, Mn 12 %) in the range 10–50 mK was measured by means of a new method that uses a metal–insulator junction (M-I.J) of known characteristics to read temperatures at one end of the sample. The same power P that crosses the sample to measure its thermal resistance flows through the M-I.J. A suitable choice of the M-I.J allows the temperature T of the upper end of the sample to rise above 20 mK. T was measured by a small size Ruthenium thermometer.